Double wall piping is typically used between tanks and dispensers, and particularly for potentially hazardous materials such as chemicals and petroleum products. Monitors used to detect leakage from this piping typically utilize vacuum or positive pressure testing methods, which can be unreliable, and cannot identify the source of failures.
The foregoing discussion reflects the current state of the art of which the present inventors are aware. Reference to, and discussion of, this information is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that no prior art patents or other references disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.